The short version of 反相色谱 fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-11-09. Anything still debated is marked as such rather than presented as settled.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
各国监管态度分化明显。俄罗斯按处方药管理，部分东欧国家留有使用记录；欧盟与美国未批准其作为药物上市，市面流通品通常标注为研究用化学品。身份差异意味着标示含量、纯度与无菌性缺少统一核查。体育领域还牵涉反兴奋剂名录，跨境携带则受目的地药品法规约束。
Semax 是人工设计的七肽，序列为 Met-Glu-His-Phe-Pro-Gly-Pro，骨架取自促肾上腺皮质激素片段 ACTH(4-10)。它于二十世纪八十年代在苏联的分子遗传学研究机构内合成。设计目标是保留该片段与注意力和记忆相关的活性，同时剔除促皮质激素释放等内分泌作用。此后俄罗斯将其登记为药品并进入临床使用。
当时的短肽研究普遍关注能否穿越血脑屏障、在低剂量下产生中枢效应，Semax 属于这一路线。鼻内给药是其主要使用方式，俄语文献报道的适应症涵盖缺血性卒中、短暂性脑缺血发作、认知功能减退以及视神经病变。这些研究大多发表在当地期刊上，样本规模与终点设置同西方试验惯例存在差异，国际同行对其临床证据的强度看法不一。
| Property | Value | Notes |
|---|---|---|
| Primary research models | Rodent studies | Largest share of published data |
| Reported markers | BDNF and NGF expression | Measured mainly in animal tissue |
| Common administration | Intranasal | Matches the registered formulation |
| Blood residence time | Minutes | Rapid enzymatic degradation |
| Evidence quality | Small trials, limited replication | Noted repeatedly in reviews |
纯度评估以反相高效液相色谱为主，通过主峰面积百分比给出粗略结果，再配合电喷雾质谱核对分子量。氨基酸分析可验证组成比例，手性色谱或毛细管电泳用于检查残基构型。常见杂质包括缺失序列的短肽、氧化产物与二聚体。由于多数市售品不附带完整检验报告，独立第三方检测常被用来核实标称值。
从分子层面看，Semax 是线性七肽，没有二硫键、糖基或脂链修饰，N 端为游离氨基，C 端为游离羧基。分子含组氨酸与谷氨酸侧链，因此在水和甲醇等极性溶剂中溶解良好，在非极性溶剂中溶解有限。计算分子量约为 814 Da，与其质子化离子的质荷比吻合，可用于质谱确认。
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
Practical handling follows from those properties. Bulk material is best divided into single-use portions soon after receipt, because each thaw exposes the whole container to moisture and temperature cycling. Vials should be allowed to reach room temperature before opening to prevent condensation on the powder. Low-binding plasticware reduces loss of dilute solutions, and sterile filtration is used when a preparation must remain free of microbial growth. Records of batch number, reconstitution date and storage history are what allow a later analytical result to be interpreted meaningfully.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
Long before compartmentalized biology like FUCA appeared, life is hypothesized to have emerged through the organization of a pre-cellular era in the RNA world. In this era, self-replicating RNA molecules would have both stored genetic information and catalyzed chemical reactions. Translation machinery and the genetic code is universally present in all known cells and viruses, indicating a single origin for biological systems (monophyly). FUCA is thought to have been the first organism capable of biological translation, using RNA molecules to convert information into peptides and produce proteins. This first translation system is thought to have formed at the same time as an error-prone early genetic code. FUCA would be the first biological system to have a genetic code that dictates specific protein assembly. The development of FUCA would have been a gradual process initially without the genetic code. FUCA is hypothesized to have arisen from the ribosome, a complex made of RNA and proteins that evolved from a more primitive ribonucleoprotein machinery. FUCA appeared when the early peptidyl transferase center first emerged and when RNA world replicators could bond amino acids into short chained oligopeptides. The first genes of FUCA most likely encoded ribosomal components, primitive tRNA-aminoacyl transferases, and other proteins that helped stabilize and maintain biological translation. These random peptides may have bound back to the single strand nucleic acid polymers which increased their stability and the robustness of the system, binding other stabilizing molecules.
2 H3N+CH2COO− → H3N+CH2CONHCH2COO− + H2O Pyrolysis of glycine or glycylglycine gives 2,5-diketopiperazine, the cyclic diamide. Glycine forms esters with alcohols. They are often isolated as their hydrochloride, such as glycine methyl ester hydrochloride. Otherwise, the free ester tends to convert to diketopiperazine.
=== Primary prevention === Primary prevention aims to reduce the risk factors before a disease or condition occurs. Sun protection is the most effective form of primary prevention of photoaging. The major methods of sun protection are sunscreen products, sun protective clothing, and reducing exposure to the sun, especially during peak sun hours (10 AM-4 PM in the spring and summer seasons). Broad-spectrum sunscreen products provide optimal coverage for protection against UV damage because they protect against both types of UVA rays (UVA1 and UVA2) along with UVB rays. Proper application methods and timing are important factors in proper sunscreen use. This includes using a proper quantity of sunscreen, applying sunscreen prior to sun exposure, and consistent reapplication (especially after exposure to water or sweat).
=== Fish glue === Fish glue is made from the bones or tissues of fish. Isinglass is made specifically from the swim bladders, and is collagen-based. Fish glues were used in Ancient Egypt and Classical Antiquity in the Mediterranean; they continued to be used in Europe in Late Antiquity and the Medieval period, and are still used in niche applications today. It is brittle when dried, so it has sometimes been mixed with plasticizers such as molasses and honey. It was used in art, book binding, woodworking, lutherie, and for gluing paper and bone.
== Predicted properties == Very few properties of flerovium or its compounds have been measured; due to its extremely limited and expensive production and the fact that it decays very quickly. A few singular properties have been measured, but for the most part, properties of flerovium remain unknown and only predictions are available.
Sources: en.wikipedia.org
== Drug withdrawn == On 18 December 2009, the European Medicines Agency recommended the withdrawal of all medicines containing benfluorex in the European Union, because their risks, particularly the risk of heart valve disease (fenfluramine-like cardiovascular side effects), are greater than their benefits. Thus Frachon et al. showed a higher rate of unexplained valvular heart disease in people taking benfluorex. Weill et al. looked at over 1 million people with diabetes demonstrating a higher hospitalization rate in benfluorex takers for valvular heart disease. In France, the medication had been marketed by Servier as an adjuvant antidiabetic under the name Mediator. The drug was on the market between 1976 and 2009, and is thought to have caused between 500 and 2,000 deaths. The drug was also used in Spain, Portugal, and Cyprus. On March 29, 2021, a French court fined Servier €2.7m (£2.3m) after finding it guilty of deception and manslaughter, with Mediator linked to the deaths of up to 2,000 people. The former executive Jean-Philippe Seta was sentenced to a suspended jail sentence of four years. The French medicines agency, accused of failing to act quickly enough on warnings about the drug, was fined €303,000. The pharmaceutical group was later additionally convicted of charges of fraud. Fenfluramine, a related drug, had been withdrawn from the market in 1997 after reports of heart valve disease, pulmonary hypertension, and development of cardiac fibrosis.
=== Religion === In general, the Houthi movement has centered its belief system on the Zaydi branch of Islam, a sect almost exclusively present in Yemen. Zaydis form about 34% of the population, with Sunnis comprising about 65%. Zaydi-led governments ruled Yemen for a thousand years up until 1962. The Houthi movement has often advocated for Zaydi revivalism in Yemen since its foundation. Although the group has framed its struggle in religious terms and put great importance on its Zaydi roots, the Houthis are not an exclusively Zaydi group. They have rejected their portrayal by others as a faction that is purportedly only interested in Zaydi-related issues. They have not publicly advocated for the restoration of the old Zaydi imamate, although analysts have argued that they might plan to restore it in the future. Most Yemenis have a low opinion of the old imamate, and Hussein al-Houthi also did not advocate the imamate's restoration. Instead, he proposed a "Guiding Eminence" (alam al-huda): an individual descended from the Prophet who would act as a "universal leader for the world". However, he never defined this position's prerogatives or how they should be appointed.
Certain functions necessary to the trial, such as monitoring and lab work, may be managed by an outsourced partner, such as a contract research organization or a central laboratory. Only 10 percent of all drugs started in human clinical trials become approved drugs. Data collection is a key activity within clinical trials and digital data collection tools can assist greatly in this effort.
We oppose so-called `harm reduction´ strategies as endpoints that promote the false notion that there are safe or responsible ways to use drugs. That is, strategies in which the primary goal is to enable drug users to maintain addictive, destructive, and compulsive behavior by misleading users about some drug risks while ignoring others. Such shortcomings arguably exist with some harm reduction measures, such as supervised injection facilities. These facilities provide users with the information and equipment necessary to avoid infection with diseases such as HIV, but leave them dependent on the black market. So users still face the health risk associated with the injection of impure street drugs and they still face the enormous financial strain of financing their addiction. In the case of heroin-assisted treatment however, users are provided with a form of pharmaceutical-grade heroin injection solution which doctors consider fit for injection. And as doctors refrain from drastic changes in dose and provide post-injection monitoring, overdoses are rare and can be quickly treated with opioid antagonists like naloxone. Thus, patients in heroin-assisted treatment are relieved from the major complex of problems that defines illicit heroin use. Synthetic heroin taken under the aforementioned conditions is not neurotoxic and has few long-term side effects beside constipation and dependency.
In Colorado, the vaccine shipments will be escorted by Colorado State Patrol officers from Denver International Airport to the state's eight distribution points; the exact plans are confidential and law enforcement will "maintain a low-key profile". Peripheral businesses may also be affected. An IBM security analyst told The New York Times that petrochemical companies are being targeted by hackers due to their central role in producing dry ice. On 21 May 2020, the FDA made public the cease-and-desist notice it had sent to North Coast Biologics, a Seattle-based company that had been selling a purported "nCoV19 spike protein vaccine". On 21 January 2021, its founder, Johnny Stine, was arrested on a federal warrant charging him with introducing misbranded drugs into interstate commerce, a misdemeanor. Stine pleaded guilty in August 2021. On 8 March 2022, he was sentenced to five years' probation and ordered to pay $246,986 in restitution.
Sources: en.wikipedia.org
=== Mental illness referred to in children's television === A 2000 study of New Zealand Children's television shows showed that a mental illness reference appeared in 59 out of 128 episodes chosen. In those 59 episodes, there were 159 references to mental illness, frequently of character descriptions. The terms "mad," "crazy," and "losing your mind" were above the three most common references. Character appearances consisted of disfigured facial features (teeth, noses, etc.) and disfigured extremities. Mental illness has also been portrayed in Walt Disney animated films. A study examined the portrayal of mental illness in Disney films and found that 85% of these films made reference to mental illness, and 21% of the characters were referred to as mentally ill. On average, 4.6 references to mental illness were made in these films, with the most commonly used terms being "mad," "crazy," or "nutty." The study highlighted how Maurice, from Beauty and the Beast, was often depicted as mentally ill, referred to as a lunatic, and was even attempted to be sent to an asylum. Another study examined 40 children's programs on Netflix, analyzing 339 episodes for references to mental illness. The study found that 23 of these programs had at least one reference to mental illness, with 58 episodes featuring such references. It also noted differences in how male and female characters with mental illness were portrayed. Male characters were often depicted as violent or aggressive, while female characters were shown as "crazy" or obsessive.
== History == ELGA Products Limited was founded in 1937 by Walter Lorch to manufacture domestic electrical appliances, but moved into water purification to overcome the problem of limescale deposits in steam irons. It developed a small cartridge-type deionizer to purify the water. ELGA collaborated with the London School of Pharmacy to develop products aimed at the hospital market, laboratories and general industry. A manufacturing unit was set up in 1959 in Lane End, Buckinghamshire, UK. During the 1960s ELGA became a global supplier of water purification systems. ELGA Group PLC was incorporated in 1984 and became part of Protean PLC in 1992. Protean PLC was acquired by Culligan Water Technologies (Northbrook Illinois) in 1997. Culligan was acquired by U.S. Filter (Palm Springs, California) in 1998. ELGA became part of USF Limited in 1999. U.S. Filter was acquired by Vivendi S.A. (Paris, France) in 2000. ELGA became part of Vivendi Water Systems Limited and then Veolia Water Systems LTD, part of the Veolia Group, in 2003. ELGA has added North American and Asian manufacturing operations to the original UK site.
=== Allotrope === The Allotrope Foundation curates an HDF5- and Triplestore-based file format called Allotrope Data Format (ADF), as well as a flat JSON representation called Allotrope Simple Model (ASM), both of which are based on the Allotrope Foundation Ontologies (AFO) and contain schemas for mass spectrometry and chromatography coupled with mass-spectrometric detectors.
This consists of a refrigeration cycle, where heat is removed from a low-temperature space or source and rejected to a high-temperature sink with the help of external work, inverse of the thermodynamic power cycle. In the power cycle, heat is supplied from a high-temperature source to the engine, part of the heat being used to produce work and the rest being rejected to a low-temperature sink. This satisfies the second law of thermodynamics. A refrigeration cycle describes the changes that take place in the refrigerant as it alternately absorbs and rejects heat as it circulates through a refrigerator. It is also applied to heating, ventilation, and air conditioning HVACR work, when describing the "process" of refrigerant flow through an HVACR unit, whether it is a packaged or split system. Heat naturally flows from hot to cold. Work is applied to cool a living space or storage volume by pumping heat from a lower temperature heat source into a higher temperature heat sink. Insulation is used to reduce the work and energy needed to achieve and maintain a lower temperature in the cooled space. The operating principle of the refrigeration cycle was described mathematically by Sadi Carnot in 1824 as a heat engine. The most common types of refrigeration systems use the reverse-Rankine vapor-compression refrigeration cycle, although absorption heat pumps are used in a minority of applications. Cyclic refrigeration can be classified as:
In the mid-afternoon on September 2, in the Ana Kalay Valley, following a similar ruse that killed 7 insurgents, 39 Green Berets, SASR soldiers and Afghan Police on five GMVs were returning to an American patrol base when they were engaged by small arms and RPG fire from four firing points, starting the Battle of Khaz Oruzgan. One Green Beret was seriously wounded, a U.S. JTAC called in a flight of F/A-18 Hornets that conducted gun runs against the insurgents and returned to drop JDAMs on a group of insurgents, as the patrol moved with their vehicles more troops were hit, they eventually arrived at the patrol base, of the 13 wounded- 7 were SASR soldiers and a Green Beret was killed; one SASR soldier was awarded the Victoria Cross for his actions during the battle.
Sources: en.wikipedia.org
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.
The compound is registered as a medicine in Russia, so clinical work has concentrated there. Trials elsewhere are few and generally small. This geographic concentration is a recognized limitation in evidence reviews.
Some fraction may reach the central nervous system through olfactory pathways, and this is often cited as the rationale for the nasal route. The size of that fraction in humans is not well quantified. Blood concentrations after nasal dosing are low, which complicates measurement.
不存在。它是依据 ACTH 的一段序列人工设计的分子，天然蛋白质中找不到与之完全相同的七肽。名称属于研究代号，而非天然物质名。